Misc Question: Blood Donation and Weight Requirements

StaciMarie1974

I am due to give blood on Thursday evening, and just looked up requirements to see if my teens would be eligible to donate as well. I see that 16-17 year olds (I have a 15 & 17 year old daughter, younger turns 16 in the fall) can donate w/ parental consent if they meet certain weight minimums based on height.

I assume the goal is to make sure the donor is healthy though I'm curious on the specifics. The general requirement for adults is 110 pounds minimum. But for under 18, there are guidelines based on height:

4'11 minimum weight 142
5'0" minimum weight 138
5'1" minimum weight 133

My 15 year old is about 5'0" though I'm not sure if she is just under or just over, and my 17 year old is almost 5'1". Both will not be eligible to donate blood due to being below the minimum weight. I'm just wondering if anyone has any clue as to the reasoning behind these #s. It seems to indicate that only overweight 16-17 year olds are wanted for blood donation.

Does anyone have additional insight?

Duchy82

It's probably to do with the amount of blood available in the body at a specific weight. The heavier you are the more blood vessels to supply the tissues therefore more blood. It probably means they would probably not be able to take the amount of blood they take as standard it's a pint in the UK (just over 500ml) without your daughters feeling the effects of missing that amount.

But I'm only taking an educated guess.

CSARdiver

This has to do with studies from the AHA donor population base. There's a history of adverse events in the system with people in the under 18 yo that height/weight.

cs2thecox

I think it's simply to do with blood volume.
Maybe the combined height/weight matrix is more accurate at measuring blood volume than just weight in isolation.

(The UK cut off is 45kg I think, but independent of height. Over 18s only too AFAIK.)

StaciMarie1974

Thanks

SafioraLinnea

Yes, it has to do with blood volume but age and growth and health are also factors. Donating blood should not have a negative impact on the person donating or it's the wrong choice. The person needs to be able to donate without risking anything for them self. A unit of blood is a fairly significant change for the body and smaller bodies tend to struggle more.

I used to donate fairly frequently but after a couple "barely okay afterward" donations I have taken a break to focus on my own health at the blood bank nurse's gentle recommendation. I was told that if I had another poor response I would not be permitted to donate again for a minimum timeframe of at least a year.